Antioxidants may Prevent "Chemo-Brain"

A new animal study shows that antioxidant therapy may protect against memory and attention problems commonly seen in cancer patients who are undergoing chemotherapy.

When cancer treatment interferes with thinking, it is sometimes called "chemo-brain" or "chemo-fog." Chemo-brain is estimated to affect about 20-30 percent of chemotherapy patients, but its cause remains unknown. The condition is generally mild and symptoms gradually improve over time after chemotherapy is completed. 

Researchers from West Virginia University School of Medicine tested whether injections with the antioxidant N-acetyl cysteine (NAC) could prevent chemo-related memory changes in rats.

One group of rats received two common cancer drugs, doxorubicin (Adriamycin®) and cyclophosphamide (Cytoxan®), four times weekly. Compared to the control animals, the rats that received chemotherapy had lower memory scores, indicating chemo-brain.

However, chemo-brain was prevented when rats received NAC injections three times weekly during chemotherapy.

Although these results, published in the journal Metabolic Brain Disease, are promising, additional research in humans is needed before recommendations can be made in humans. In the meantime, cancer patients should not take antioxidant supplements unless under the supervision of their healthcare providers. There has been concern that antioxidants may theoretically interfere with the effectiveness of chemotherapy in humans, but study results are inconclusive.

In a related review article, researchers have found that antioxidant supplementation during chemotherapy may reduce toxicities, thereby reducing side effects. While most studies showed that antioxidants had positive effects on toxicity, statistical power and poor study quality were concerns with some studies.

Comments

[Ree]

In response to Rollie, chemo works on all rapidly growing cells, not just the malignant, cancerous cells. I think the antioxidant effects they are suggesting work against the other toxic side effects, not the primary actions of the drugs to treat cancer. Being able to reduce some of the side effects is important because the use of chemo is often limited to them. Some patients are not eligible for certain therapy over time because they experienced too many side effects early in the therapy.

[jessica]

I wonder how many patients would be willing to try this remedy for chemo brain. Cancer patients often will do anything possible to get into remission. If a treatment might improve their quality of life, but could also inhibit the effectiveness of their chemotherapy, I do not feel that patients will be very willing to try this remedy and possibly slow or reverse their progress toward disease remission.

[HL]

The condition called "chemo-brain" affects a large number of cancer patients receiving chemotherapy. Patients with this condition suffer from memory loss and have difficulty focusing and concentrating. This study seems to show good benefit of NAC in preventing the negative effects of chemo; however, positive effects of NAC were studied on animals not humans. Besides, since it is still not fully clear whether antioxidant treatment influences the effectiveness of cancer drugs during treatment, one option is to begin antioxidant therapy with N-acetylcysteine a week after the last chemotherapy dose.

[LK]

Since this data were from an animal study, I definitely agree that this potential use of NAC needs further exploration with human studies; however, it is not ethical to test an agent that may interfere with chemotherapy in a population of cancer patients. I doubt a trial like this would be conducted in the US, but maybe in other countries we’ll find large trials for this use and its safety.

[PK]

There are many different medications used in chemotherapy with multiple mechanisms of action. It seems irresponsible to recommend a global treatment for such a poorly defined adverse effect as chemo-brain. Further studies are definitely needed to establish how high-dose antioxidant therapy may impact chemotherapy efficacy.

Another blogger mentioned the lack of information regarding the patients' diets. It has long been established that cancer patients should be eating well-balanced diets and that the best way to absorb nutrients is though food. Are we again looking for a quick fix when what is needed is proper diet?

[cyndi feigenbaum]

N-acetyl cysteine is not an antioxidant found in foods. It has unique properties of its own. It can stimulate the production of glutathione, increasing its levels in the brain. I wonder if whey could be a safer supplement to increase glutathione levels than NAC. Theoretically, what makes NAC so unique? I have also read that NAC has a positive effect on the brain and can be used to treat mood disorders.

[cyndi feigenbaum]

Raising Vitamin D levels can delay many forms of cancer. I refer to the October 2008 Townsend Journal. I would be careful not to count out the patients' intuition and knowledge when it comes to his/her own life and being in a remissive state. The old adage to seek professional help still holds. But be sure your doctor understands nutrition and its value. There are many natural "cures." In the same journal, it is reported that an extract from eggplant can cure, yes cure, skin cancer (excluding melanoma). This cure has been around for many years. This shows the blind ignorance of many doctors. I can write a book on this subject and its political implications. So don't count antioxidants and herbs out.